Technical Field
The present disclosure generally relates to electric devices and, more particularly, to electric motor cooling systems and devices.
Description of the Related Art
The concern over the volume and cost of fossil fuels available in the future is fueling the proliferation of electric powered devices, including vehicles such as automobiles, trucks, motorcycles, scooters, golf carts, and utility carts, as well as other devices such as lawnmowers, chain saws, and the like. The motors that drive such vehicles and other electrically powered devices during operation generate heat due to copper energy losses, iron energy losses, and mechanical losses, among other things.
As the demand increases for more powerful motors to drive devices faster, with more acceleration and power, the need to cool such motors efficiently without increasing noise, weight, and complexity will increase. Examples of techniques used to cool electric motors include enclosing the motor assemblies in housings and passing cooling liquids through the housings to facilitate dissipation of heat, or providing fans that provide increased airflow to the internal and/or external components of the motor. While these techniques can contribute to the cooling of an electric motor, they each have drawbacks, such as added weight, increased noise, low efficiencies, and added complexity.
By way of example, cooling systems utilizing conventional housings may include a plurality of grooves formed around spaced apart concentric ribs. The cooling liquid is discharged to flow around each groove to cool a motor assembly. However, the heat exchange coefficients of such housings are often compromised due to lower flow rates and fouling effects, among other things. Additionally, such housings add weight, manufacturing costs, and inefficient use of space. Further, such housings typically comprise multiple components, which lead to time consuming assembly processes resulting in high manufacturing and labor costs. By way of example, such housings generally include separate inner and outer members and upper and lower covers to seal the opposing ends of the inner and outer members, for example, in U.S. Publication No. 2013/0342046. Assembling such conventional housing requires multiple steps to fasten each component to the other.
With the ever-expanding interest in reducing dependence on fossil fuels and improving the environment, electric vehicles and electrically powered devices will continue to increase in popularity. Vehicle and device owners and manufacturers of such items will be interested in motor cooling systems that are easy to assemble/disassemble, improve heat exchange efficiency, reduce manufacture and labor costs, and are reliable.